mount.nfs: mount to NFS server failed: System Error: No route to host.

When enabling NFS service on a Cent OS Linux server, the client could not mount the NFS shares on the server. Got the error below:

mount.nfs: mount to NFS server failed: System Error: No route to host.

The reason is: the iptables firewall blocks the NFS service ports. (NOTE: by default, iptables firewall is enabled on Redhat like Linux, e.g. CentOS, Fedora).

To allow the NFS service ports:

1. Edit /etc/sysconfig/nfs and uncomment/add the following lines:

   LOCKD_TCPPORT=32803
   LOCKD_UDPPORT=32769
   MOUNTD_PORT=892
   STATD_PORT=662
   STATD_OUTGOING_PORT=2020
   

2. Restart the nfs services:

   sudo /etc/init.d/nfs restart
   sudo /etc/init.d/nfslock restart
   

3. check if the ports are open as expected:

   rpcinfo -p localhost

      program vers proto   port  service
       100000    4   tcp    111  portmapper
       100000    3   tcp    111  portmapper
       100000    2   tcp    111  portmapper
       100000    4   udp    111  portmapper
       100000    3   udp    111  portmapper
       100000    2   udp    111  portmapper
       100021    1   udp  32769  nlockmgr
       100021    3   udp  32769  nlockmgr
       100021    4   udp  32769  nlockmgr
       100021    1   tcp  32803  nlockmgr
       100021    3   tcp  32803  nlockmgr
       100021    4   tcp  32803  nlockmgr
       100011    1   udp    875  rquotad
       100011    2   udp    875  rquotad
       100011    1   tcp    875  rquotad
       100011    2   tcp    875  rquotad
       100003    2   tcp   2049  nfs
       100003    3   tcp   2049  nfs
       100003    4   tcp   2049  nfs
       100227    2   tcp   2049  nfs_acl
       100227    3   tcp   2049  nfs_acl
       100003    2   udp   2049  nfs
       100003    3   udp   2049  nfs
       100003    4   udp   2049  nfs
       100227    2   udp   2049  nfs_acl
       100227    3   udp   2049  nfs_acl
       100005    1   udp    892  mountd
       100005    1   tcp    892  mountd
       100005    2   udp    892  mountd
       100005    2   tcp    892  mountd
       100005    3   udp    892  mountd
       100005    3   tcp    892  mountd
       100024    1   udp    662  status
       100024    1   tcp    662  status
   

4. edit /etc/sysconfig/iptables and add the following rules:

   -A INPUT -m state --state NEW -m udp -p udp --dport 2049 -j ACCEPT
   -A INPUT -m state --state NEW -m tcp -p tcp --dport 2049 -j ACCEPT
   -A INPUT -m state --state NEW -m udp -p udp --dport 111 -j ACCEPT
   -A INPUT -m state --state NEW -m tcp -p tcp --dport 111 -j ACCEPT
   -A INPUT -m state --state NEW -m udp -p udp --dport 32769 -j ACCEPT
   -A INPUT -m state --state NEW -m tcp -p tcp --dport 32803 -j ACCEPT
   -A INPUT -m state --state NEW -m udp -p udp --dport 892 -j ACCEPT
   -A INPUT -m state --state NEW -m tcp -p tcp --dport 892 -j ACCEPT
   -A INPUT -m state --state NEW -m udp -p udp --dport 875 -j ACCEPT
   -A INPUT -m state --state NEW -m tcp -p tcp --dport 875 -j ACCEPT
   -A INPUT -m state --state NEW -m udp -p udp --dport 662 -j ACCEPT
   -A INPUT -m state --state NEW -m tcp -p tcp --dport 662 -j ACCEPT
   

5. Restart iptables:

   sudo service iptables restart

Now you can mount the NFS server on the client side.

Note:

The above solution is for the Redhat Like Linux (RHEL, CentOS, Fedora).

See Also:

• Linux Iptables Allow NFS Clients to Access the NFS Server
• How to configure NFS on Linux
• Any luck on setting fixed port on lockd?